diff --git a/aiida_aimall/__init__.py b/aiida_aimall/__init__.py
index 4c2b63e..328085a 100644
--- a/aiida_aimall/__init__.py
+++ b/aiida_aimall/__init__.py
@@ -4,4 +4,4 @@
 A plugin to interface AIMAll with AiiDA
 """
 
-__version__ = "0.2.7"
+__version__ = "0.2.8"
diff --git a/aiida_aimall/controllers.py b/aiida_aimall/controllers.py
index 1598d82..52c8551 100644
--- a/aiida_aimall/controllers.py
+++ b/aiida_aimall/controllers.py
@@ -211,7 +211,7 @@ def get_inputs_and_processclass_from_extras(self, extras_values):
         code = orm.load_code(self.code_label)
         structure = self.get_parent_node_from_extras(extras_values)
         inputs = {
-            "fragment_label": extras_values[0],
+            "fragment_label": Str(extras_values[0]),
             "code": code,
             "parameters": Dict(self.g16_sp_params),
             "structure_str": structure,